Artificial stomach

ABSTRACT

An artificial stomach for replacing the normal stomach of a patient is disclosed. The artificial stomach comprises a food reservoir adapted to collect food, an inlet connected to a first opening to the food reservoir and further being adapted to upstream connect to the patient&#39;s gastrointestinal tract. The artificial stomach further comprises an outlet connected to a second opening of the food reservoir and further being adapted to downstream connect to the patient&#39;s gastrointestinal tract. An outer wall encloses both the food reservoir and a servo reservoir for regulating the size of the food reservoir, the food reservoir and the servo reservoir being separated by a flexible inner wall.

This application is a continuation of U.S. patent application Ser. No.14/252,247, filed Apr. 14, 2014, and issued as U.S. Pat. No. 9,763,768,which is a continuation of U.S. patent application Ser. No. 13/122,825,filed Apr. 6, 2011, and issued as U.S. Pat. No. 8,696,761, which is theU.S. National Phase of International Application No. PCT/SE2009/051157,filed 12 Oct. 2009, which designated the U.S. and claims the priorityfrom Swedish Application No. 0802160-2, filed Oct. 10, 2008, and claimsthe benefit of U.S. Provisional Application No. 61/227,815, filed on 23Jul. 2009, the entire contents of each of which are hereby incorporatedby reference in this application.

FIELD OF INVENTION

The present invention generally relates to implantation and moreparticularly to an artificial stomach implantable into a human or animalpatient. The invention also relates to methods of placing and using anartificial stomach.

BACKGROUND

Stomach cancer is a serious condition and to save life it has been shownthat the whole stomach needs to be surgically removed although thecancer may be small. Patients with stomach cancer normally get theirwhole stomach surgically removed, the operation called totalgastrectomy. This means the oesophagus and the intestine is suturedtogether. These patients quality of life is dramatically reduced. Theirfood supply is normally without both reservoir and valves—creatingserious problems in terms of ability to eat and ability to keep theweight.

The placement of the normal stomach 102 of a person 100 is seen inFIG. 1. A more detailed view of the anatomy of a normal stomach is shownin FIG. 2 a. In the gastrointestinal tract, the oesophagus 202 normallytranscends into the stomach 204 at the cardia area 206. The stomach 204then transcends downstream into the duodenum 212 of the intestine 210 atthe pyloris 208. For persons having their stomach 204 surgically removed(hereinafter referred to as patients), one method is to surgicallyconnect the oesophagus 202 directly to the intestine 210. The result ofsuch a surgical operation is shown in FIG. 2 b. The most proximal partof the intestine 210, i.e. the duodenum 212, is not able to reach to theoesophagus 202 and therefore the proximal jejunum 214 is cut and thedistal side sutured to the oesophagus 202 and the proximal part of thejejunum 214 comprising duodenum 212 and the gall connection proximal issutured end to side to jejunum 214 further distal creating a so calledRoux-en-Y-connection.

Because it is not easy to reach the oesophagus 202 with the intestine210, they are normally connected end to end like a tube with out anyreservoir or valves. Normally the cardia 206 (the ring muscle betweenthe stomach and oesophagus) keeps the food passage way closed to avoidreflux problems but cardia 206 is normally removed when performing aRoux-en-Y operation.

The overall result is a very unpleasant situation for the patient. Thepatients have large difficulties to keep their weight and normally feelthemselves in a really bad shape, with several food related badfeelings. The situation for the patients is so complicated that studieshave shown a dramatic increase in suicide in this group of patients.

Furthermore, there exist also other possible solutions, such asxenotransplantations and intravenous drip. Xenotransplantation is amethod where an organ from an animal is transplanted to a patient.However, the immune rejection effects are serious and the method is nota usable alternative. The method of living with a nutrition drip hasvarious disadvantages, for instance the patient needs to bring dropletequipment and loses also the moment of eating. The situation of life fora patient with nutrition drip is far from natural.

The ability to replace the stomach with an artificial stomach wouldincrease quality of life dramatically for these patients. Such anartificial stomach may be used independently of the reason for removingthe stomach.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a solution to the abovedescribed problem for patients which have had their stomach surgicallyremoved.

The invention is based on the realisation that an implanted artificialstomach can replace a natural stomach, which has been removed.

Thus, according to one embodiment of the invention there is provided anartificial stomach for replacing the normal stomach of a patient,comprising: a food reservoir adapted to collect food, an inlet connectedto a first opening of the food reservoir and further being adapted toupstream connect to the patient's gastrointestinal tract, and an outletconnected to a second opening of the food reservoir and further beingadapted to downstream connect to the patient's gastrointestinal tract.

In the preferred embodiment:

An artificial stomach for replacing the normal stomach of a patient,comprising:

a food reservoir adapted to collect food,

an inlet connected to a first opening of the food reservoir and furtherbeing adapted to upstream connect to the patient's gastrointestinaltract, and

an outlet connected to a second opening of the food reservoir andfurther being adapted to downstream connect to the patient'sgastrointestinal tract,

wherein an outer wall encloses both the food reservoir and a servoreservoir for regulating the size of the food reservoir, the foodreservoir and the servo reservoir being separated by a flexible innerwall, where further both the food reservoir wall and the wall of theservo reservoir comprise parts of the outer wall and the flexible innerwall.

Preferable the artificial stomach comprises an inlet valve connectedbetween the patient's gastrointestinal tract and the first opening ofthe food reservoir

The artificial stomach may be implantable in the patient's abdomen andmay have the inlet further adapted to upstream connect to theoesophagus. The inlet may also be further adapted to upstream connect tothe intestine.

In one embodiment the inlet valve is connected between the inlet and thefirst opening of the food reservoir or the artificial stomach comprisesan inlet valve unit comprising an inlet valve connected between thepatient's gastrointestinal tract and the first opening of the foodreservoir.

The inlet valve is preferable adapted to open correlated to when food inthe gastrointestinal tract upstream is transported down. Alternativelythe inlet valve is adapted to open correlated to when a contracting waveis propagating along the gastrointestinal tract upstream or adapted toopen correlated to when food is reaching the inlet valve.

In another embodiment the inlet valve unit comprising at least oneconnector adapted to upstream connect the inlet to the patient'sgastrointestinal tract. The connector may comprise a sleeve adapted tocover a part of the wall of the gastrointestinal tract, wherein thesleeve preferable has a structure adapted to promote in-growth of humantissue into the sleeve.

The artificial stomach preferable the inlet valve unit may furthercomprising a burp output, wherein the burp output further comprises aburp valve connecting the food reservoir with the inlet valve proximalto said burp valve.

The artificial stomach preferable have an outer wall that encloses boththe food reservoir and a servo reservoir for regulating the size of thefood reservoir, the food reservoir and the servo reservoir beingseparated by a flexible inner wall, where further both the foodreservoir wall and the wall of the servo reservoir comprise parts of theouter wall and the flexible inner wall, wherein said servo reservoir isadapted to be filled with fluid in small steps, wherein the foodreservoir is adapted to be emptied by the servo reservoir in smallsteps, when said servo reservoir is filled with said fluid in smallsteps, thereby emptying food in small steps into the intestine, whensaid artificial stomach is implanted.

The food reservoir is normally adapted to empty step by step, smallportions of food at a time.

In yet another embodiment the artificial stomach have an the outletvalve adapted to functioning passively and opens related to a volumedecrease in the food reservoir.

The artificial stomach normally include a servo reservoir, adapted tohave a variable size and to be filled with different amounts of fluid.The servo reservoir in this embodiment is adapted to have a shapeallowing variation in size without limitation from surrounded fibrosis,covering the implant when implanted.

The artificial stomach further may include a hydraulic fluid reservoir,hydraulically connected to said servo reservoir and a pump for fluidconnecting the fluid supply reservoir to the servo reservoir. Preferablesaid pump is adapted to reversible move fluid between the servoreservoir and the hydraulic fluid reservoir.

In the artificial stomach according to another embodiment, an outer wallencloses both the food reservoir and a servo reservoir for regulatingthe size of the food reservoir, the food reservoir and the servoreservoir being separated by a flexible inner wall, where further boththe food reservoir wall and the wall of the servo reservoir compriseparts of the outer wall and the flexible inner wall.

The servo reservoir may comprise a bellow.

The artificial stomach may in another embodiment have said servoreservoir adapted to be regulated by manually pressing a pumpingreservoir in fluid connection with the servo reservoir, and may furthercomprising a reversed servo, wherein a small volume in the pumpingreservoir is adapted to be moved manually to the servo reservoir in aclosed system, compressed with a higher force per area unit and whereinsaid servo reservoir is adapted to create a larger volume change in asecond closed system, having less force per area unit.

Preferable the artificial stomach having the outer wall being rigid. Inone embodiment the stomach food part comprises the food reservoir andthe servo reservoir, and where the hydraulic fluid reservoir isseparated from the stomach food part by the rigid outer wall and isfurther enclosed by a fluid reservoir wall.

In yet another embodiment the food reservoir is adapted to increase involume when filled with food when the patient is eating, thereby causinga reduction in the volume of the servo reservoir, in turn moving fluidfrom said servo reservoir to said hydraulic fluid reservoir.

The artificial stomach outlet is further normally adapted to downstreamconnect to the intestine.

The artificial stomach preferable comprising an outlet valve connectedbetween the second opening of the food reservoir and the outlet, whereinthe outlet valve is adapted to open when the food reservoir should beemptied. Alternatively the outlet valve is adapted to open at aregulated rate.

In the artificial stomach according to another embodiment, the foodreservoir, the inlet, and the outlet are manufactured of a biocompatiblematerial.

The artificial stomach preferably comprises at least one connectoradapted to upstream connect the inlet to the patient's gastrointestinaltract, or downstream connect the outlet to the patient'sgastrointestinal tract, wherein the connector preferable comprises asleeve adapted to cover a part of the wall of the gastrointestinaltract, and wherein the sleeve preferable has a structure adapted topromote in-growth of human tissue into the sleeve.

Thus the artificial stomach preferably comprises a connector connectingthe intestine to the outlet connector and/or a connector connecting theoesophagus or intestine to the inlet connector.

In one embodiment the artificial stomach comprising a food handlingsystem, which may be adapted to;

mechanically handling food in the food reservoir.

moving the food around in the food reservoir.

cut the food in the food reservoir, preferable comprising electricallydriven rotating knifes adapted to cut the food in the food reservoir.

squeeze the food in the food reservoir.

chemically handling food in the food reservoir.

release at least one liquid in the food reservoir, the liquid beingadapted to treat the food in the food reservoir.

The liquid may comprises at least one of; an acid, an enzyme, ananti-bacterial substance.

In yet another embodiment the artificial stomach comprising a cleaningsystem adapted to clean the surface of the food reservoir by releasingat least one liquid into the food reservoir.

The liquid may comprises a cleaning substance and/or an anti-bacterialsubstance.

The artificial stomach may further comprising a special container,wherein the special container preferable is adapted to accumulate anddistribute at least one liquid to the food handling system and/or,wherein the special container is adapted to accumulate and distribute atleast one liquid to the cleaning system.

The artificial stomach or the system connected thereto may include afood sensor arranged outside of the food reservoir on the inlet side ofthe same in order to register when food is to arrive to the artificialstomach, wherein preferable the food sensor is arranged at theoesophagus wall.

The system in one embodiment include, the registration that food is toarrive to the artificial stomach is made by registering change in volumeof the oesophagus or change of the curvature or elongation of theoesophagus wall.

In yet another embodiment the artificial stomach, comprising at leastone connector adapted to be connected to the oesophagus or the intestineof a patient, the connector comprising a conduit fixedly attached at afirst, proximal end on the outside the artificial stomach and in fluidconnection to the food passageway, where the proximal part of theconduit is formed like a tube, and distal to the tube a bulge is formed.

Preferable a blocking ring is arranged to be pushed against the bulge,the ring having an inner diameter less than the outer diameter of saidbulge but large enough to allow the intestinal/oesophageal wall to beplaced between said ring and said tube, thereby adapted to stop saidintestinal/oesophageal wall from slipping away from the tube.

Preferable is included a flexible sleeve arranged to be rolled uponitself and then unrolled to cover part of the tube and the oesophagus orintestine, which is arranged to be pulled over the second end of theconduit sufficiently far so as to extend also over the bulge.

In one embodiment of the artificial stomach a blocking ring is arrangedto be pushed over the flexible sleeve against the bulge, the ring havingan inner diameter less than the outer diameter of said bulge but largeenough to allow the intestinal/oesophageal wall to be placed betweensaid ring and said tube, thereby adapted to stop saidintestinal/oesophageal all from slipping away from the tube.

The artificial stomach in one embodiment includes a return conduitarranged between the fluid reservoir and the servo reservoir for movingfluid between said servo reservoir and said hydraulic fluid reservoirvia said return conduit.

In one embodiment of the artificial stomach; moving of fluid from theservo reservoir to the hydraulic fluid reservoir is done by that thefood entering the food reservoir from the inlet presses on the flexiblewall of the servo reservoir thus emptying fluid from there to thehydraulic fluid reservoir via a return conduit.

In another embodiment of the artificial stomach; moving of fluid fromthe servo reservoir to the hydraulic fluid reservoir is done by that afood sensor sends signals to the pump when food is to enters the foodreservoir, the pump thus pumping out to said food corresponding amountof fluid from the servo reservoir to the hydraulic fluid reservoir.

In yet another embodiment the emptying of the food reservoir is director indirect regulated by a gear construction. Preferable the gearconstruction is driven by a motor.

The artificial stomach according to another embodiment, comprises aservo system connected to said motor, to save force against longerstroke.

Preferable a servo system is connected to said motor and a drive shaftconnected to said servo system, wherein the drive shaft preferabledirect or indirect affects the emptying of said food reservoir.

In another embodiment the drive shaft comprises two ends comprising athread, spiral ridges turning in different directions at the two ends,further comprising a nut placed on the shaft at each end of the driveshaft, the food reservoir comprising two movable walls of saidreservoir, wherein said nuts is adapted to be placed onto said movingwalls, the motor adapted to change the volume of said food reservoir,when turning said drive shaft placed into said nuts, by moving saidmovable walls.

The artificial stomach may comprise an elastic material, abio-compatible material and/or silicone.

Suitably, is provided at least one layer. For example, a metal layer, aParylene layer, a polytetrafluoroethylene layer or a polyurethane layer.Suitably, one of the layers may be made of metal, silicon or PTFE. Thelayers may comprise multiple layers in any order. The volume fillingdevice may comprise an outer surface layer of silicone, polyurethane,Teflon®, or polytetrafluoroethylene, metal, parylene, PTFE or acombination thereof. The volume filling device may comprise an innersurface layer of silicone, polyurethane, Teflon®, orpolytetrafluoroethylene, metal, parylene, PTFE or a combination thereof.Other combinations of layers include but not limited to an inner surfacelayer of polytetrafluoroethylene and an outer layer of silicone, aninner surface layer of polytetrafluoroethylene, an intermediate layer ofsilicone, and an outer layer of Parylene, an inner surface layer ofpolyurethane and an outer layer of silicone, and an inner surface layerof polyurethane, an intermediate layer of silicone, and an outer layerof Parylene.

The fluid may comprises large molecules, such as iodine molecules, toprevent diffusion.

The system may include a fastening device for the artificial stomachcomprising a first unit adapted to be implanted at a first side of theabdominal wall in the patient, and where a second unit is adapted to beimplanted in the abdominal cavity of the patient at a second side of theabdominal wall, and where the artificial stomach is fastened to thefastening device, wherein preferable the first or second unit has acircular or elliptical cross-sectional shape when viewed from outsidethe patient's body.

In one embodiment the first and second units are covered by a cover madeof material providing protection, wherein preferable the cover seals thefastening device which also may be a control assembly, therebyprotecting possible electronics and other sensitive components of thecontrol assembly.

The system may include an interconnecting device constitutes amechanical interconnection between the first and second units so thatthe fastening device is kept in place by the body tissue.

In another embodiment the interconnecting device is hollow so as tohouse various wires, hoses etc. electrically or hydraulicallyinterconnecting the first and second units.

According to one embodiment the device is a part of a system that maycomprise a switch for manually and non-invasively controlling thedevice. The switch is according to one embodiment an electric switch anddesigned for subcutaneous implantation.

According to another embodiment the system further comprises a hydraulicdevice having a hydraulic reservoir, which is hydraulically connected tothe device. The device could be manually regulated by pressing thehydraulic reservoir or automatically operated using a wireless remotecontrol.

The wireless remote control system comprises, according to oneembodiment, at least one external signal transmitter and an internalsignal receiver implantable in the patient for receiving signalstransmitted by the external signal transmitter. The system could operateusing a frequency, amplitude, or phase modulated signal or a combinationthereof.

According to one embodiment the wireless control signal comprises ananalogue or a digital signal, or a combination of an analogue anddigital signal. It is also conceivable that the signal comprises anelectric or magnetic field, or a combined electric and magnetic field.According to another embodiment the wireless remote control furthertransmits a carrier signal for carrying the wireless control signal,said signal could comprise a digital, analogue or a combination ofdigital and analogue signals.

For supplying the system with energy it comprises, according to oneembodiment, a wireless energy-transmission device for non-invasivelyenergizing said device. According to said embodiment theenergy-transmission device transmits energy by at least one wirelessenergy signal, which for example comprises a wave signal such as anultrasound wave signal, an electromagnetic wave signal, an infraredlight signal, a visible light signal, an ultra violet light signal, alaser light signal, a micro wave signal, a radio wave signal, an x-rayradiation signal and a gamma radiation signal.

It is further conceivable that the energy signal comprises an electricor magnetic field, or a combined electric and magnetic field, which canbe transmitted using a carrier signal such as a digital, analogue or acombination of digital and analogue signals.

According to one embodiment the system further comprises an energysource for powering said device, which can be an implantable or externalenergy source or a combination thereof, in which case the internal andexternal energy sources can be in electric communication.

In an embodiment in which the system comprises an internal energysource, a sensor sensing a functional parameter correlated to thetransfer of energy for charging the internal energy source may beprovided, it is furthermore conceivable that a feedback device forsending feedback information from the inside to the outside of thepatient's is provided.

According to another embodiment the system further comprises a sensorsensing a parameter such as a functional or physical parameter. Saidfunctional parameter is, according to one embodiment, correlated to thetransfer of energy for charging an internal energy source implantable inthe patient. Said embodiment could furthermore comprise a feedbackdevice for sending feedback information from inside to the outside ofthe patient's body and an implantable internal control unit forcontrolling the sensing. Above mentioned physical parameter could be oneof body temperature, blood pressure, blood flow, heartbeats andbreathing, and the sensor could be a pressure or motility sensor.

According to one embodiment the system could further comprise anexternal data communicator and an implantable internal data communicatorcommunicating with the external data communicator, wherein the internalcommunicator feeds data related to said device or the patient to theexternal data communicator and/or the external data communicator feedsdata to the internal data communicator. It is also conceivable that thesystem further comprises an operation device for operating said device,such as a motor or a pump, which can be electrically, hydraulically orpneumatically operated.

According to another embodiment the system has an energy-transmissiondevice for transmitting wireless energy, wherein the wireless energy isused to directly power the operation device through for example creatingkinetic energy for the operation of said device.

In embodiments where the system comprises an energy-transmission devicefor transmitting wireless energy, an energy-transforming device fortransforming the wireless energy from a first form into a second formmay be provided. Said energy-transforming device may directly power bythe second form of energy. The energy could be in the form of a directcurrent or pulsating direct current, or a combination of a directcurrent and pulsating direct current, or an alternating current or acombination of a direct and alternating current, it is also conceivablethat the energy is in the form of magnetic energy, kinetic energy, soundenergy, chemical energy, radiant energy, electromagnetic energy, photoenergy, nuclear energy or thermal energy. The system may furthercomprise an implantable accumulator for storing energy.

To prevent damage of the system it is conceivable that it comprisesimplantable electrical components including at least one voltage levelguard and/or at least one constant current guard.

In a preferred embodiment, the system comprises at least one switchimplantable in the patient for manually and non-invasively controllingthe apparatus

In another preferred embodiment, the system comprises a wireless remotecontrol for non-invasively controlling the apparatus.

In a preferred embodiment, the system comprises a hydraulic operationdevice for operating the apparatus.

In one embodiment, the system comprises comprising a motor or a pump foroperating the apparatus.

The method of filling the servo reservoir with fluid step by step insmall steps so that the food reservoir is emptied or at leastessentially emptied in small steps which results in food is received bythe intestine in small subsequent portions.

Further preferred embodiments are defined by the dependent claims.

Please note that all the embodiments or features of an embodiment aswell as any method or step of a method could be combined in any way ifsuch combination is not clearly contradictory. Please also note that thedescription in general should be seen as describing both an apparatus ordevice adapted to perform a method as well as this method in itself.

BRIEF DESCRIPTION OF DRAWINGS

The invention is now described, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic drawing illustrating a normal stomach in vivo in aperson.

FIG. 2A is a more detailed drawing illustrating the normal stomach invivo in a person.

FIG. 2B is a schematic drawing illustrating the digestive system for apatient, having its normal stomach removed with the prior art ROUX-en-Ymethod.

FIG. 3 is a schematic drawing illustrating an artificial stomachaccording to the invention in vivo in a patient.

FIG. 4A is a block diagram illustrating an artificial stomach, inaccordance with one embodiment.

FIG. 4B is a block diagram illustrating an artificial stomach, inaccordance with another embodiment.

FIG. 5 is a drawing illustrating a hydraulically one artificial stomachaccording to a further embodiment.

FIG. 6 is a drawing showing an electrically operated artificial stomachaccording to a yet further embodiment.

FIG. 7A is a flat schematic view illustrating a connector of anartificial stomach in accordance with another embodiment.

FIG. 7B is a second schematic view illustrating a connector of anartificial stomach in accordance with another embodiment.

FIG. 8 is a drawing illustrating a system comprising an artificialstomach implanted in a patient in accordance with another embodiment.

FIGS. 9-32C are schematic drawings of various embodiments ofarrangements for powering and controlling the artificial stomach.

FIG. 33 is a drawing illustrating a hydraulically operated artificialstomach according to a further embodiment.

FIG. 34 is a flow chart describing a method of implanting an artificialstomach according to the invention into a human or animal patient.

FIG. 35 is a side view of an embodiment of a fastening device for anartificial stomach according to the invention mounted to a body tissue.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Briefly described, the present invention provides a solution forenabling a more natural digestive process for patients which have theirnatural stomach removed, by providing and implanting an artificialstomach into the patient's body,

The term “food” used in this description will hereinafter represent foodor liquid, as well as any combination of food and liquid eaten or drunkby a patient. With “patient” means any human or animal, suitable to haveits normal stomach replaced by an artificial stomach. The “oesophagus”is also found to be spelled esophagus. Correspondingly, oesophageal mayalso be spelled esophageal.

Prior art has been described above with reference to FIGS. 1, 2 a, and 2b.

A patient having an implanted artificial stomach in accordance with oneembodiment of the present invention will now be described, withreference to FIG. 3. The artificial stomach 10 is implanted in the bodyof the patient 200, preferably at the same place as the normal stomachwas removed from. The artificial stomach 10 may in this example becontrolled by any suitable means, such as a remote control (not shown),which is either placed outside the patient's body or is implanted in thebody.

An artificial stomach in accordance with an exemplary embodiment of thepresent invention will now be described with reference to FIG. 4aillustrating a block diagram. The artificial stomach 10 comprises aninlet 11, connected to a first opening of a food reservoir 12, and anoutlet 13 connected to a second opening of the food reservoir 12. Theinlet 11 is connected upstream to the oesophagus of a patient, andreceives good when the patient eats or drinks. The inlet 11 feeds thefood to the food reservoir 12 that collects the food. The outlet 13 isconnected downstream to the intestine of the patient, and outputs thecollected food. Alternatively, the inlet 11 may instead be connected tothe intestine, at a point upstream from the point the outlet 13 isconnected to. This is useful for patients having their normal stomachremoved and their oesophagus connected to their intestine. Preferably,the artificial stomach 10 may be adapted to be implanted in the abdomenof the patient, but may also be designed to be used on other areasinside or outside the patient's body.

Another embodiment, different from the embodiment described above, willnow be described with reference to FIG. 4b . The artificial stomachaccording to this embodiment comprises the corresponding inlet 11, foodreservoir 12, and outlet 13, as described above, but comprises alsovarious additional components. The artificial stomach 10 comprises aninlet valve 14 and an optional outlet valve 15, the valves opening andclosing the food reservoir 12. The inlet valve 14 is adapted to opencorrelated to when food and/or a contracting wave in the oesophagus istransported longitudinally down the oesophagus. Optionally, the inletvalve 14 may instead be adapted to open correlated to when food and/or acontracting wave in the oesophagus is reaching the inlet valve 14. Theoutlet valve 15 is adapted to empty the food reservoir 12 relativelyslowly into the intestine, and the outlet valve may be adapted to eitheropen stepwise or steplessly. To connect the artificial stomach 10 to theoesophagus or intestine, an inlet connector 17 and an outlet connector18 may be used. Such connectors, which will be described in detail belowwith reference to FIGS. 7a and 7b , are described in the provisionalU.S. patent applications Nos. 60/960,790 and 60/960,791, which areincorporated herein by reference. The food will be transported through afood passageway 16, defined as comprising all components which come intocontact with the food, i.e. including the food reservoir 12, the inletvalve 14, the outlet valve 15, and the connectors 17 and 18. This foodpassageway is preferably manufactured of a biocompatible material.Preferably, the food reservoir 12 may be adapted to empty relativelyslowly into the intestine. A food sensor 117 may be arranged outside ofthe food reservoir 12 on its inlet side in order to register when foodis to arrive to the food reservoir 12. The food sensor 117 is e.g.arranged at the position shown in FIG. 4b , but may as has been earliermentioned be situated e.g at the oesophagus wall (see FIG. 33). Theregistration that food is to arrive to the food reservoir 12 is e.g.made by registering change in volume of the oesophagus or change of thecurvature or elongation of the oesophagus wall in which case the foodsensor is preferably arranged on or at the oesophagus wall as shown inFIG. 33.

A food handling system 19 is connected to the food reservoir 12 is beadapted to handle the food in the food reservoir 12 mechanically and/orchemically. A mechanical thud handling system may include at least oneof: a moving system moving the food around in the food reservoir 12, asqueezing system squeezing the food in the food reservoir 12, a cuttingsystem cutting the food in the food reservoir 12 (e.g. by rotatingknifes), or any other system suitable for mechanically handling the foodin the food reservoir 12. On the other hand, a chemical food handlingsystem may be adapted to release various chemicals into the foodreservoir 12 for treating the food, e.g. by releasing digestionfacilitating chemicals (e.g. an enzyme, an acid, etc.), or disinfectingchemicals (e.g. an anti-bacterial substance) into the food. A cleaningsystem 20 is provided and may be adapted to treat the food passageway 16with cleaning chemicals, e.g. including any anti-bacterial substance.

To enable the releasing of digestion-facilitating chemicals,disinfecting chemicals, or cleaning chemicals in the food reservoir 12,the artificial stomach 10 comprises a special container 21 adapted toaccumulate these chemicals before distributing them to the foodreservoir 12. Furthermore, an injection port 22 connected to the specialcontainer 21 is also provided to enable filling or re-filling ofchemicals to the special container 21. The injection port 22 is adaptedto be placed subcutaneously on the patient's body, and is furtheradapted to be injected with at least one of: an anti-bacterial liquid,an acid, a cleaning fluid, a contrast medium, or any other suitableliquid.

In order to operate the artificial stomach 10, an operating device 40 isprovided. The operating device 40 may electrically and/or hydraulicallyoperate the artificial stomach 10, e.g. by operating the food handlingsystem 19, or the cleaning system 20. In the case when the artificialstomach 10 is electrically operated, the operation device 40 iselectrically powered and may e.g. comprise an electrical motor. In thecase when the artificial stomach 10 is hydraulically operated, theoperation device 40 is instead a hydraulic operation device. However, askilled person will understand that the operation device 40 may also bedesigned to be powered and operated in different ways. For instance, thefood handling system 19 may be operated hydraulically, but be poweredelectrically.

The artificial stomach 10 is adapted for various functions, e.g.mechanically food handling, chemical food handling, or cleaning the foodpassage way 16, and at least one of the functions may be regulated fromoutside the patient's 200 body. For regulating a function from outsidethe patient's 200 body, a subcutaneous switch may be adapted to bepressed by the patient. Alternatively, when the artificial stomach 10 ishydraulically operated, a hydraulic reservoir having a connection withthe hydraulic operation device 40 may be adapted to be manually pressedby the patient 200 for regulating the operation device 40. The hydraulicreservoir may be the special container 21, and may be placed invasivelyor non-invasively. When the operation device 40 is powered electrically,the artificial stomach 10 in one alternative may comprise an internalenergy source (e.g. a battery or an accumulator), a remote control and areceiver for the information signals from the remote control. Thesecomponents are adapted to enable for the patient to regulate theartificial stomach from outside the body. Different ways of controllingor regulating the artificial stomach will be described below withreference to FIGS. 9-32.

However, a skilled person will understand that the components of thedescribed embodiment may be varied and he is also capable to constructan artificial stomach comprising various combinations of thesecomponents.

An artificial stomach in accordance with an exemplary embodiment of thepresent invention will now be described with reference to FIG. 5, andwith further reference to FIG. 2 and FIG. 4. The artificial stomach 10is preferably manufactured in order to have an anatomical structuresimilar to the structure of the normal stomach, and is adapted to beplaced in the abdomen of a patient. In this embodiment the artificialstomach 10 is hydraulically operated. The artificial stomach 10 isconnected to the gastrointestinal tract, upstream the inlet 11 isconnected to the oesophagus 202 and downstream the outlet 13 isconnected to the distal end of the cut jejunum 214. However, a skilledperson will understand that the artificial stomach 10 may be implantedon various places of the gastrointestinal tract. For instance, a patient200 having the stomach removed by the Roux-en-Y method, may have theremaining gastrointestinal tract (oesophagus 202 sutured with distal endof jejunum 214) cut and connected to the inlet 11 and outlet 13 of anartificial stomach 10. In that case, an upstream part of the jejunum 214may be connected to the inlet 11 of the artificial stomach 10 and adownstream part of the jejunum 214 may be connected to the outlet 13 ofthe artificial stomach 10. A regulating bellow 502 of the artificialstomach 10 is connected through a hose 506 with a hydraulic reservoir, aservo reservoir, 504. The hydraulic reservoir 504 is placedsubcutaneously in the patient 200, outside the abdominal wall 510, i.e.between the patient's skin 508 and the abdominal wall 510. The patientis then capable to operate the artificial stomach 10 by pressing orsqueezing the hydraulic reservoir 504. Squeezing the hydraulic reservoir504 will regulate the flow of hydraulic fluid to the regulating bellow502. Alternatively, the hydraulic reservoir 504 may be placed on anothersuitable placement in the patient's 200 body and the squeezing of thehydraulic reservoir 504 may then be performed indirectly by e.g.pressing a subcutaneous switch, or activating a subcutaneously placedpump, etc. The switch and the pump may then be pressed and activated,respectively, by the patient 200. The food reservoir of the artificialstomach is optionally adapted to increase in volume when filled withfood when the patient is eating, thereby causing a change in the volumeof the servo reservoir, in turn moving fluid between said servoreservoir and said hydraulic fluid reservoir

An artificial stomach in accordance with an exemplary embodiment of thepresent invention will now be described with reference to FIG. 6, andwith further reference to FIG. 2 and FIG. 4. The artificial stomach 10is manufactured in order to have an anatomical structure similar to thestructure of the normal stomach, and is adapted to be placed in theabdomen of a patient. In this embodiment the artificial stomach 10 ismechanically operated. The artificial stomach 10 is connected to thegastrointestinal tract; upstream the inlet 11 is connected to theoesophagus 202 and downstream the outlet 13 is connected to the distalend of the cut jejunum 214. However, a skilled person will understandthat the artificial stomach 10 may be implanted on various places of thegastrointestinal tract. For instance, a patient 200 having the stomachremoved by the Roux.-en-Y method, may have the remaininggastrointestinal tract (oesophagus 202 sutured with distal end ofjejunum 214) cut and connected to the inlet 11 and outlet 13 of anartificial stomach 10. In that case, an upstream part of the jejunum 214may be connected to the inlet 11 of the artificial stomach 10 and adownstream part of the jejunum 214 may be connected to the outlet 13 ofthe artificial stomach 10. The artificial stomach 10 is regulated by agear 74 driven by a motor 40. An operating unit 606, operating the motor40 is placed subcutaneously in the patient 200, outside the abdominalwall 510, i.e. between the patient's skin 508 and the abdominal wall510. The motor 40 is connected with the operating unit 606 and is alsopowered by the operating unit via a connector 608. The operating unit606 may have a subcutaneous switch and the patient 200 is capable tooperate the artificial stomach 10 by pressing the switch. Alternatively,the operating unit may be controlled by a remote control, or othersuitable unit from outside the patient's 200 body. The food reservoir ofthe artificial stomach is optionally adapted to increase in volume whenfilled with food when the patient is eating, thereby causing a change inthe gear 74 driven by the motor, e.g. by that the gear is allowed tomove due to influence of the increase of food in the food reservoir.Said change also causes a change in the position of the bellow.According to this embodiment, the emptying of the food reservoir isdirect or indirect regulated by a gear construction, preferably drivenby a motor.

A connector (at 720) (earlier referred to as 17 and 18) in accordancewith an exemplary embodiment of the present invention will now bedescribed with reference to FIG. 7a and FIG. 7b , and with furtherreference to FIG. 3 and FIG. 4. The artificial stomach 10 comprises atleast one connector (at 720) adapted to be connected to the oesophagus202 or the intestine 204 of a patient. The connector (at 720) comprisesa preferably circular conduit 726, which is fixedly attached at a first,proximal end on the outside the artificial stomach 10 and in fluidconnection to the food passageway. The proximal part of the conduit 726is formed like a tube 718, and distal to the tube 718 a bulge 728 isformed. A flexible sleeve 720 is roiled upon itself and then unrolled tocover part of the tube 718 and tubular tissue 722 (oesophagus 202 orintestine 204), which, in this case, is pulled over the second end 724of the conduit 726 sufficiently far so as to extend also over the bulge728. The flexible sleeve 720 has a structure adapted to facilitatein-growth of tissue through the flexible sleeve 720 to achieve a longterm connection between the flexible sleeve 720 and theintestinal/oesophageal wall 722. After the flexible sleeve 720 has beenunrolled over the tubular tissue 722, a blocking ring 730 is pushed overthe flexible sleeve against the bulge 728. The ring 730 has an innerdiameter less than the outer diameter of said bulge 728 but large enoughto allow the intestinal/oesophageal wall 722 to be placed between saidring 730 and said tube 718, thereby adapted to stop saidintestinal/oesophageal wall 722 to slip away from the tube 718. After awhile, the threads 732 sutured to the intestinal/oesophageal wall 722and the wall 734 of the conduit 726 (FIG. 7b ) will have been absorbedby the patient's 200 body and, about during the same time, living tissuewill have formed in and connected the intestinal/oesophageal wall 722 tothe in-growth layer 736 of the flexible sleeve 720. Therefore, as theintestinal oesophageal wall 722 tends to be pulled off from the secondend 724 of the conduit 726, the blocking ring 730 will also be moved,press the intestinal/oesophageal wall 722 and the flexible sleeve 720against the bulge 728 and thereby prohibit any further slippage of theintestinal/oesophageal wall 722 over the bulge 728. The frictioncoefficient between the blocking ring 730 and the outer surface of theflexible sleeve 720 should be higher than the friction coefficient whichthe outer surface of the conduit's wall 734 has in relation to theintestinal/oesophageal wall 722. As has been described above, theconnector (at 720) preferably comprises a flexible sleeve 720, but it isalso possible as an option to leave oust said sleeve 720 from theconnector, in which case the blocking ring 730 is arranged with asomewhat smaller diameter compared to the one shown in FIGS. 7a and 7bin order to preserve the functionality described above.

System

An artificial stomach system, generally designated 28 and comprising anartificial stomach as described above will now be described withreference to FIGS. 8-32.

The system of FIG. 8 comprises an artificial stomach 10 placed in theabdomen of the patient 200. An internal energy source in the form of animplanted energy transforming, device 30 is adapted to supply energyconsuming components of the artificial stomach system with energy via apower supply line 32. An external energy transmission device 34 includesa wireless remote control transmitting a wireless signal, which isreceived by a signal receiver which may be incorporated in the implantedenergy transforming device 30 or be separated therefrom. The implantedenergy transforming device 30 transforms energy from the signal intoelectric energy which is supplied via the power supply line 32.

The system of FIG. 8 is shown in a more generalized block diagram formin FIG. 9, wherein the patient's skin 36, generally shown by a verticalline, separates the interior of the patient to the right of the linefrom the exterior to the left of the line.

FIG. 10 shows an embodiment of the invention identical to that of FIG.9, except that a reversing device in the form of an electric switch 38operable by polarized energy also is implanted the patient for reversingthe artificial stomach 10. The wireless remote control of the externalenergy transmission device 34 transmits a wireless signal that carriespolarized energy and the implanted energy transforming device 30transforms the wireless polarized energy into a polarized current foroperating the electric switch 38. When the polarity of the current isshifted by the implanted energy transforming device 30 the electricswitch 38 reverses the function performed by the artificial stomach 10.

FIG. 11 shows an embodiment of the invention identical to that of FIG.9, except that an operation device 40 implanted in the patient forregulating the artificial stomach 10 is provided between the implantedenergy transforming device 30 and the artificial stomach 10. Thisoperation device can be in the form of a motor 40, such as an electricservomotor. The motor 40 is powered with energy from the implantedenergy transforming device 30, as the remote control of the externalenergy transmission device 34 transmits a wireless signal to thereceiver of the implanted energy transforming device 30.

FIG. 12 shows an embodiment of the invention identical to that of FIG.9, except that it also comprises an operation device is in the form oran assembly 42 including a motor/pump unit 78 and a regulation reservoir46 is implanted in the patient. In this case the artificial stomach 10is hydraulically operated, i.e. hydraulic fluid is pumped by themotor/pump unit 44 from the regulation reservoir 46 through a conduit 48to the artificial stomach 10 to operate the artificial stomach, andhydraulic fluid is pumped by the motor/pump unit 44 back from theartificial stomach 10 to the regulation reservoir 46 to return theartificial stomach to a starting position. The implanted energytransforming device 30 transforms wireless energy into a current, forexample a polarized current, for powering the motor/pump unit 44 via anelectric power supply line 50.

Instead of a hydraulically operated artificial stomach 10, it is alsoenvisaged that the operation device comprises a pneumatic operationdevice. In this case, pressurized air can be used for regulation and theregulation reservoir is replaced by an air chamber and the fluid isreplaced by air.

In all of these embodiments the implanted energy transforming device 30may include a rechargeable accumulator like a battery or a capacitor tobe charged by the wireless energy and supplies energy for any energyconsuming part of the device.

The external energy transmission device 34 is preferably wireless andmay include a remotely controlled control device for controlling thedevice from outside the human body.

Such a control device may include a wireless remote control as well as amanual control of any implanted part to make contact with by thepatient's hand most likely indirect for example a button to press placedunder the skin.

FIG. 13 shows an embodiment of the invention comprising the externalenergy transmission device 34 with its wireless remote control, theartificial stomach 10, in this case hydraulically operated, and theimplanted energy transforming device 30, and further comprising ahydraulic fluid reservoir 52, a motor/pump unit 44 and an reversingdevice in the form of a hydraulic valve shifting device 54, allimplanted in the patient. Of course the hydraulic operation could easilybe performed by just changing the pumping direction and the hydraulicvalve may therefore be omitted. The remote control may be a deviceseparated from the external energy transmission or included in the same.The motor of the motor/pump unit 44 is an electric motor. In response toa control signal from the wireless remote control of the external energytransmission device 34, the implanted energy transforming device 30powers the motor/pump unit 44 with energy from the energy carried by thecontrol signal, whereby the motor/pump unit 44 distributes hydraulicfluid between the hydraulic fluid reservoir 52 and the artificialstomach 10. The remote control of the external energy transmissiondevice 34 controls the hydraulic valve shifting device 54 to shift thehydraulic fluid flow direction between one direction in which the fluidis pumped by the motor/pump unit 44 from the hydraulic fluid reservoir52 to the artificial stomach 10 to operate the artificial stomach, andanother opposite direction in which the fluid is pumped by themotor/pump unit 44 back from the artificial stomach 10 to the hydraulicfluid reservoir 52 to return the artificial stomach to a startingposition.

FIG. 14 shows an embodiment of the invention identical to that of FIG.13, except that an internal control unit 56 controlled by the wirelessremote control of the external energy transmission device 34, anaccumulator 58 and a capacitor 60 also are implanted in the patient. Theinternal control unit 56 arranges storage of electric energy receivedfrom the implanted energy transforming device 30 in the accumulator 58,which supplies energy to the artificial stomach 10. In response to acontrol signal from the wireless remote control of the external energytransmission device 34, the internal control unit 56 either releaseselectric energy from the accumulator 58 and transforms the releasedenergy via power lines 62 and 64, or directly transforms electric energyfrom the implanted energy transforming device 30 via a power line 66,the capacitor 60, which stabilizes the electric current, a power line 68and the power line 64, for the operation of the artificial stomach 10.

The internal control unit is preferably programmable from outside thepatient's body. In a preferred embodiment, the internal control unit isprogrammed to regulate the artificial stomach 10 to stretch the stomachaccording to a pre-programmed time-schedule or to input from any sensorsensing any possible physical parameter of the patient or any functionalparameter of the device.

In accordance with an alternative, the capacitor 60 in the embodiment ofFIG. 14 may be omitted. In accordance with another alternative, theaccumulator 58 in this embodiment may be omitted.

FIG. 15 shows an embodiment of the invention identical to that of FIG.9, except that a battery 70 for supplying energy for the operation ofthe artificial stomach 10 and an electric switch 72 for switching theoperation of the artificial stomach 10 also are implanted in thepatient. The electric switch 72 is operated by the energy supplied bythe implanted energy transforming device 30 to switch from an off mode,in which the battery 70 is not in use, to an on mode, in which thebattery 70 supplies energy for the operation of the artificial stomach10.

FIG. 16 shows an embodiment of the invention identical to that of FIG.15, except that an internal control unit 56 controllable by the wirelessremote control of the external energy transmission device 34 also isimplanted in the patient. In this case, the electric switch 72 isoperated by the energy supplied by the implanted energy transformingdevice 30 to switch from an off mode, in which the wireless remotecontrol is prevented from controlling the internal control unit 56 andthe battery is not in use, to a standby mode, in which the remotecontrol is permitted to control the internal control unit 56 to releaseelectric energy from the battery 70 for the operation of the artificialstomach 10.

FIG. 17 shows an embodiment of the invention identical to that of FIG.16, except that an accumulator 58 is substituted for the battery 70 andthe implanted components are interconnected differently. In this case,the accumulator 58 stores energy from the implanted energy transformingdevice 30. In response to a control signal from the wireless remotecontrol of the external energy transmission device 34, the internalcontrol unit 56 controls the electric switch 72 to switch from an offmode, in which the accumulator 58 is not in use, to an on mode, in whichthe accumulator 58 supplies energy for the operation of the artificialstomach 10.

FIG. 18 shows an embodiment of the invention identical to that of FIG.17, except that a battery 70 also is implanted in the patient and theimplanted components are interconnected differently. In response to acontrol signal from the wireless remote control of the external energytransmission device 34, the internal control unit 56 controls theaccumulator 58 to deliver energy for operating the electric switch 72 toswitch from an off mode, in which the battery 70 is not in use, to an onmode, in which the battery 70 supplies electric energy for the operationof the artificial stomach 10.

Alternatively, the electric switch 72 may be operated by energy suppliedby the accumulator 58 to switch from an off mode, in which the wirelessremote control is prevented from controlling the battery 70 to supplyelectric energy and is not in use, to a standby mode, in which thewireless remote control is permitted to control the battery 70 to supplyelectric energy for the operation of the artificial stomach 10.

It should be understood that the switch should be interpreted in itsbroadest embodiment. This means an Field-programmable gate array (FPGA)or a D/A converter or any other electronic component or circuit mayswitch power on and off preferably being controlled from outside thebody or by an internal control unit.

FIG. 19 shows an embodiment of the invention identical to that of FIG.15, except that a motor 40, a mechanical reversing device in the form ofa gear 74, and an internal control unit 56 for controlling the gear 74also are implanted in the patient. The internal control unit 56 controlsthe gear 74 to reverse the function performed by the artificial stomach10 (mechanically operated). Even simpler is to switch the direction ofthe motor electronically.

FIG. 20 shows an embodiment of the invention identical to that of FIG.20 except that the implanted components are interconnected differently.Thus, in this case the internal control unit 56 is powered by thebattery 70 when the accumulator 58, suitably a capacitor, activates theelectric switch 72 to switch to an on mode. When the electric switch 72is in its on mode the internal control unit 56 is permitted to controlthe battery 70 to supply, or not supply, energy for the operation of theartificial stomach 10.

FIG. 21 schematically shows conceivable combinations of implantedcomponents of the apparatus for achieving various communication options.Basically, there are the artificial stomach 10, the internal controlunit 56, motor or pump unit 44, and the external energy transmissiondevice 34 including the external wireless remote control. As alreadydescribed above the wireless remote control transmits a control signalwhich is received by the internal control unit 56, which in turncontrols the various implanted components of the apparatus.

A feedback device, preferably in the form of a sensor 76, may beimplanted in the patient for sensing a physical parameter of thepatient, such as a contraction wave in the oesophagus informing thepatient is eating. The internal control unit 56, or alternatively theexternal wireless remote control of the external energy transmissiondevice 34, may control the artificial stomach 10 in response to signalsfrom the sensor 76. A transceiver may be combined with the sensor 76 forsending information on the sensed physical parameter to the externalwireless remote control. The wireless remote control may comprise asignal transmitter or transceiver and the internal control unit 56 maycomprise a signal receiver or transceiver. Alternatively, the wirelessremote control may comprise a signal receiver or transceiver and theinternal control unit 56 may comprise a signal transmitter ortransceiver. The above transceivers, transmitters and receivers may beused for sending information or data related to the artificial stomach10 from inside the patient's body to the outside thereof.

Alternatively, the sensor 76 may be arranged to sense a functionalparameter of the artificial stomach 10.

Where the motor/pump unit 44 and battery 70 for powering the motor pumpunit 44 are implanted, the battery 70 may be equipped with a transceiverfor sending information on the condition of the battery 70. To be moreprecise, when charging a battery or accumulator with energy feed backinformation related to said charging process is sent and the energysupply is changed accordingly.

FIG. 21 shows an alternative embodiment wherein the artificial stomach10 is regulated from outside the patient's body. The artificial stomachsystem 28 comprises an artificial stomach 10 connected to a battery 70via a subcutaneous switch 80. Thus, the regulation of the artificialstomach 10 is perfumed non-invasively by manually pressing thesubcutaneous switch, whereby the operation of the artificial stomach 10is switched on and off it will be appreciated that the shown embodimentis a simplification and that additional components, such as an internalcontrol unit or any other part disclosed in the present application canbe added to the artificial stomach system.

FIG. 23 shows an alternative embodiment, wherein the artificial stomachsystem 28 comprises an artificial stomach 10 in fluid connection with ahydraulic fluid reservoir 52. Non-invasive regulation is performed bymanually pressing the hydraulic reservoir connected to the artificialstomach 10.

A further embodiment of a system according to the invention comprises afeedback device for sending information from inside the patient's bodyto the outside thereof to give feedback information related to at leastone functional parameter of the artificial stomach or system or aphysical parameter of the patient, thereby optimizing the performance ofthe system.

One preferred functional parameter of the device is correlated to thetransfer of energy for charging the internal energy source.

In FIG. 24, an arrangement is schematically illustrated for supplying anaccurate amount of energy to an artificial stomach system 28 implantedin a patient, whose skin 36 is indicated by a vertical line. Anartificial stomach 10 is connected to an implanted energy transformingdevice 30, likewise located inside the patient, preferably just beneaththe patient's skin 36. Generally speaking, the implanted energytransforming device 30 may be placed in the abdomen, thorax, musclefascia (e.g. in the abdominal wall), subcutaneously, or at any othersuitable location. The the implanted energy transforming device 30 isadapted to receive wireless energy E transmitted from an external energysource 34 a provided in the external energy transmission device 34located outside the patient's skin 36 in the vicinity of the implantedenergy transforming, device 30.

As is well known in the art, the wireless energy E may generally betransferred by means of any suitable Transcutaneous Energy Transfer(TET) device, such as a device including a primary coil arranged in theexternal energy source 34 a and an adjacent secondary coil arranged inthe implanted energy transforming device 30. When an electric current isfed through the primary coil, energy in the form of a voltage is inducedin the secondary coil which can be used to operate an artificialstomach, e.g. after storing the incoming energy in an energy storingdevice or accumulator, such as a battery or a capacitor. However, thepresent invention is generally not limited to any particular energytransfer technique, TET devices or energy storing devices, and any kindof Wireless energy may be used.

The amount of energy received inside the body to the device may becompared with the energy used by the device. The term used by the deviceis then understood to include also energy stored by the device. Theamount of transferred energy can be regulated by means of an externalcontrol unit 34 b controlling the external energy source 34 a based onthe determined energy balance, as described above. In order to transferthe correct amount of energy, the energy balance and the required amountof energy can be determined by means of an internal control unit 56connected to the artificial stomach 10. The internal control unit 56 maythus be arranged to receive various measurements obtained by suitablesensors or the like, not shown, measuring certain characteristics of theartificial stomach 10, somehow reflecting the required amount of energyneeded for proper operation of the artificial stomach 10. Moreover, thecurrent condition of the patient may also be detected by means ofsuitable measuring devices or sensors, in order to provide parametersreflecting the patient's condition. Hence, such characteristics and/orparameters may be related to the current state of the artificial stomach10, such as power consumption, operational mode and temperature, as wellas the patient's condition reflected by, e.g., body temperature, bloodpressure, heartbeats and breathing.

Furthermore, an energy storing device or accumulator 58 may optionallybe connected to the implanted energy transforming device 30 foraccumulating received energy for later use by the artificial stomach 10.Alternatively or additionally, characteristics of such an accumulator,also reflecting the required amount of energy, may be measured as well.The accumulator may be replaced by a battery, and the measuredcharacteristics may be related to the current state of the battery, suchas voltage, temperature, etc. in order to provide sufficient voltage andcurrent to the artificial stomach 10, and also to avoid excessiveheating, it is clearly understood that the battery should be chargedoptimally by receiving a correct amount of energy from the implantedenergy transforming device 30, i.e. not too little or too much. Theaccumulator may also be a capacitor with corresponding characteristics.

For example, battery characteristics may be measured on a regular basisto determine the current state of the battery, which then may be storedas state information in a suitable storage means in the internal controlunit 56. Thus, whenever new measurements are made, the stored batterystate information can be updated accordingly. In this way, the state ofthe battery can be “calibrated” by transferring a correct amount ofenergy, so as to maintain the battery in an optimal condition.

Thus, the internal control unit 56 is adapted to determine the energybalance and/or the currently required amount of energy, (either energyper time unit or accumulated energy) based on measurements made by theabove-mentioned sensors or measuring devices on the artificial stomach10, or the patient, or an energy storing device if used, or anycombination thereof. The internal control unit 56 is further connectedto an internal signal transmitter 82, arranged to transmit a controlsignal reflecting the determined required amount of energy, to anexternal signal receiver 34 c connected to the external control unit 34b. The amount of energy transmitted from the external energy source 34 amay then be regulated in response to the received control signal.

Alternatively, sensor measurements can be transmitted directly to theexternal control unit 34 b wherein the energy balance and/or thecurrently required amount of energy can be determined by the externalcontrol unit 34 b, thus integrating the above-described function of theinternal control unit 56 in the external control unit 34 b. In thatcase, the internal control unit 56 can be omitted and the sensormeasurements are supplied directly to the internal signal transmitter 82which sends the measurements over to the external signal receiver 34 cand the external control unit 34 b. The energy balance and the currentlyrequired amount of energy can then be determined by the external controlunit 34 b based on those sensor measurements.

Hence, the present solution employs the feed back of informationindicating the required energy, which is more efficient than previoussolutions because it is based on the actual use of energy that iscompared to the received energy, e.g. with respect to the amount ofenergy, the energy difference, or the energy receiving rate as comparedto the energy rate used by the artificial stomach. The artificialstomach may use the received energy either for consuming or for storingthe energy in an energy storage device or the like. The differentparameters discussed above would thus be used if relevant and needed andthen as a tool for determining the actual energy balance. However, suchparameters may also be needed per se for any actions taken internally tospecifically operate the artificial stomach.

The internal signal transmitter 82 and the external signal receiver 34 cmay be implemented as separate units using suitable signal transfermeans, such as radio, IR (Infrared) or ultrasonic signals.Alternatively, the internal signal transmitter 82 and the externalsignal receiver 34 c may be integrated in the implanted energytransforming device 30 and the external energy source 34 a,respectively, so as to convey control signals in a reverse directionrelative to the energy transfer, basically using the same transmissiontechnique. The control signals may be modulated with respect tofrequency, phase or amplitude.

To conclude, the energy supply arrangement illustrated in FIG. 24 mayoperate basically in the following manner. The energy balance is firstdetermined by the internal control unit 56. A control signal reflectingthe required amount of energy is also created by the internal controlunit 56, and the control signal is transmitted from the internal signaltransmitter 82 to the external signal receiver 34 c. Alternatively, theenergy balance can be determined by the external control unit 34 binstead depending on the implementation, as mentioned above. In thatcase, the control signal may carry measurement results from varioussensors. The amount of energy emitted from the external energy source 34a can then be regulated by the external control unit 34 b, based on thedetermined energy balance, e.g. in response to the received controlsignal. This process may be repeated intermittently at certain intervalsduring Ongoing energy transfer, or may be executed on a more or lesscontinuous basis during the energy transfer.

The amount of transferred energy can generally be regulated by adjustingvarious transmission parameters in the external energy source 34 a, suchas voltage, current, amplitude, wave frequency and pulsecharacteristics.

A method is thus provided for controlling transmission of wirelessenergy supplied to an electrically operable artificial stomach implantedin a patient. The wireless energy E is transmitted from an externalenergy source located outside the patient and is received by an internalenergy receiver located inside the patient, the internal energy receiverbeing connected to the artificial stomach for directly or indirectlysupplying received energy thereto. An energy balance is determinedbetween the energy received by the internal energy receiver and theenergy used for the artificial stomach. The transmission of wirelessenergy E from the external energy source is then controlled based on thedetermined energy balance.

A system is also provided for controlling transmission of wirelessenergy supplied to an electrically operable artificial stomach implantedin a patient. The system is adapted to transmit the wireless energy Efrom an external energy source located outside the patient which isreceived by an implanted energy transforming device located inside thepatient, the implanted energy transforming device being connected to theartificial stomach for directly or indirectly supplying received energythereto. The system is further adapted to determine an energy balancebetween the energy received by the implanted energy transforming deviceand the energy used for the artificial stomach, and control thetransmission of wireless energy E from the external energy source, basedon the determined energy balance.

The functional parameter of the device is correlated to the transfer ofenergy for charging the internal energy source.

In yet an alternative embodiment, the external source of energy iscontrolled from outside the patient's body to release electromagneticwireless energy, and released electromagnetic wireless energy is usedfor operating the artificial stomach.

In another embodiment, the external source of energy is controlling fromoutside the patient's body to release non-magnetic wireless energy, andreleased non-magnetic wireless energy is used for operating theartificial stomach.

Those skilled in the art will realize that the above various embodimentsaccording to FIGS. 13-25 could be combined in many different ways. Forexample, the electric switch 38 operated polarized energy could beincorporated in any of the embodiments of FIGS. 11, 14-20, the hydraulicvalve shifting device 54 could be incorporated in the embodiment of FIG.12, and the gear 74 could be incorporated in the embodiment of FIG. 11.Please observe that the switch simply could mean any electronic circuitor component.

Wireless transfer of energy for operating the artificial stomach hasbeen described to enable non-invasive operation. It will be appreciatedthat the artificial stomach can be operated with wire bound energy aswell. On such example is shown in FIG. 25, Wherein an external switch 84is interconnected between the external energy source 34 a and anoperation device, such as an electric motor regulating the artificialstomach 10, by means of power lines 86 and 88. An external control unit34 b controls the operation of the external switch to effect properoperation of the artificial stomach 10.

Hydraulic or Pneumatic Powering

FIGS. 26-29 show in more detail block diagrams of four different ways ofhydraulically or pneumatically powering an artificial stomach accordingto the invention.

FIG. 26 shows an artificial stomach system as described above. Thesystem comprises an artificial stomach 10 and further a separateregulation reservoir 46, a one way pump 44 and an alternate valve 54.

FIG. 27 shows the artificial stomach 10 and a regulation reservoir 46.By moving the wall of the regulation reservoir or changing the size ofthe same in any other different way, the adjustment of the artificialstomach may be performed without any valve, just free passage of fluidany time by moving the reservoir wall.

FIG. 28 shows the artificial stomach 10, a two way pump 44 and theregulation reservoir 46.

FIG. 29 shows a block diagram of a reversed servo system with a firstclosed system controlling a second closed system. The servo systemcomprises a regulation reservoir 46 and a servo reservoir 90. The servoreservoir 90 mechanically controls an artificial stomach 10 via amechanical interconnection 94. The artificial stomach has anexpandable/contactable cavity. This cavity is preferably expanded orcontracted by supplying hydraulic fluid from the larger adjustablereservoir 92 in fluid connection with the artificial stomach 10.Alternatively, the cavity contains compressible gas, which can becompressed and expanded under the control of the servo reservoir 90.

The servo reservoir 90 can also be part of the artificial stomachitself.

In one embodiment, the regulation reservoir is placed subcutaneous underthe patient's skin and is operated by pushing the outer surface thereofby means of a finger. This artificial stomach system is illustrated inFIGS. 30a -c. In FIG. 30a , a flexible subcutaneous regulation reservoir46 is shown connected to a bulge shaped servo reservoir 90 by means of aconduit 48. This bellow shaped servo reservoir 90 is comprised in a aflexible artificial stomach 10. In the state shown in FIG. 30a , theservo reservoir 90 contains a minimum of fluid and most fluid is foundin the regulation reservoir 46. Due to the mechanical interconnectionbetween the servo reservoir 90 and the artificial stomach 10, the outershape of the artificial stomach 10 is contracted, i.e., it occupies lessthan its maximum volume. This maximum volume is shown with dashed linesin the Fig.

FIG. 30b shows a state wherein a user, such as the patient in with theartificial stomach is implanted, presses the regulation reservoir 46 sothat fluid contained. therein is brought to flow through the conduit 4and into the servo reservoir 90, which, thanks to its bellow shape,expands longitudinally. This expansion in turn expands the artificialstomach 10 so that it occupies its maximum volume, thereby stretchingthe stomach wall (not shown), which it contacts.

The regulation reservoir 46 is preferably provided with means 46 a forkeeping its shape after compression. This means, which is schematicallyshown in the Fig., will thus keep the artificial stomach 10 in astretched position also when the user releases the regulation reservoir.In this way, the regulation reservoir essentially operates as agaron/off switch for the artificial stomach system.

An alternative embodiment of hydraulic or pneumatic operation will nowbe described with reference to FIGS. 32 and 33 a-c. The block diagramshown in FIG. 31 comprises with a first closed system controlling asecond closed system. The first system comprises a regulation reservoir46 and a servo reservoir 90. The servo reservoir 90 mechanicallycontrols a larger adjustable reservoir 92 via a mechanicalinterconnection 94. An artificial stomach 10 having anexpandable/contactable cavity is in turn controlled by the largeradjustable reservoir 92 by supply of hydraulic fluid from the largeradjustable reservoir 92 in fluid connection with the artificial stomach10.

An example of this embodiment will now be described with reference toFIG. 32a -c. Like in the previous embodiment, the regulation reservoiris placed subcutaneous under the patient's skin and is operated bypushing the outer surface thereof by means of a finger. The regulationreservoir 46 is in fluid connection with a bellow shaped servo reservoir90 by means of a conduit 48. In the first closed system comprising parts46, 48, 90 shown in FIG. 30a , the servo reservoir 90 contains a minimumof fluid and most fluid is found in the regulation reservoir 46.

The servo reservoir 90 is mechanically connected to a larger adjustablereservoir 92, in this example also having a bellow shape but with alarger diameter than the servo reservoir 90. The larger adjustablereservoir 92 is in fluid connection with the artificial stomach 10. Thismeans that when a user pushes the regulation reservoir 46, therebydisplacing fluid from the regulation reservoir 46 to the servo reservoir90, the expansion of the servo reservoir 90 will displace a largervolume of fluid from the larger adjustable reservoir 92 to theartificial stomach 10. In other words, in this reversed servo, a smallvolume in the regulation reservoir is compressed with a higher force andthis creates a movement of a larger total area with less force per areaunit.

Like in the previous embodiment described above with reference to FIGS.31a -c, the regulation reservoir 46 is preferably provided with means 46a for keeping its shape after compression. This means, which isschematically shown in the Fig., will thus keep the artificial stomach10 in a stretched position also when the user releases the regulationreservoir. In this way, the regulation reservoir essentially operates asan on/off switch for the artificial stomach system.

An artificial stomach in accordance with an exemplary embodiment of thepresent invention will now be described with reference to FIG. 33, andwith further reference to FIGS. 4a-b and 30a -c. The artificial stomach10 is preferably manufactured in order to have an anatomical structuresimilar to the structure of the normal stomach, and is adapted to beplaced in the abdomen of a patient. In this embodiment the artificialstomach 10 is hydraulically operated. The artificial stomach 10 isconnected to the gastrointestinal tract, upstream the inlet 11 isconnected to the oesophagus 202 and downstream the outlet 13 isconnected to the distal end of the cut jejunum 214.

The artificial stomach 10 has a stomach food part, which is enclosed byan outer wall 550 manufactured from a rigid material. This rigid outerwall encloses two reservoirs: a food reservoir 12 and a servo reservoir90, which are separated by a flexible inner wall 552. A hydraulic fluidreservoir 52 is separated from the stomach food part by the rigid outerwall 550 and is further enclosed by a fluid reservoir wall 556, whichfluid reservoir wall 556 preferably is flexible but may as an option berigid. If the fluid reservoir wall 556 is flexible, it may be arrangedto flex in a way similar to that of the regulation reservoir wall 46shown in FIGS. 30a and 30 b.

The food reservoir 12 is adapted to receive and treat the foodmechanically and/or chemically. The hydraulic fluid reservoir 52 isadapted to comprise a hydraulic fluid to be fed through conduits 44 a,44 b to the servo reservoir 90. A pump 44 connected to the conduits 44 aand 44 b is adapted to move the hydraulic fluid between the hydraulicfluid reservoir 52 and the servo reservoir 90.

By manufacturing the walls 550, 552, 554, and 556 of materials of theabove defined qualities and employing the pump 44 to feed the hydraulicfluid between the hydraulic fluid reservoir 52 and the servo reservoir90 in an alternating direction, a mechanical treatment is achieved bysqueezing the food in the food reservoir 12, as will now be describedwith reference to FIGS. 4b and 33.

Initially, food is allowed to enter into the food reservoir 12,optionally by opening the inlet valve 14 while maintaining the optionaloutlet valve 15 in a closed position (see FIG. 4b ). This food mayincrease the volume of the food reservoir 12 and thereby compress theservo reservoir 90 so that part of the fluid contained therein is movedto the hydraulic fluid reservoir 52. The inlet valve is closed and fluidis moved repeatedly between the hydraulic fluid reservoir 52 and theservo reservoir 90. When fluid is moved into the servo reservoir 90, theinner wall 552 presses against the food contained in the food reservoir12, thereby treating it in a way similar to that of the walls of anatural stomach. Furthermore, by releasing various chemicals a chemicaltreatment is achieved, as described above.

Emptying the food reservoir 12 may be done in different ways dependingon if the optional outlet valve 15 is arranged at the outlet end of theartificial stomach or not.

When the food contained in the food reservoir has been sufficientlytreated, and if an outlet valve 15 is present, the outlet valve 15 isopened and the servo reservoir 90 is filled with fluid so that the foodreservoir 12 is emptied or at least essentially emptied. The foodreservoir is adapted to empty step by step, small portions at a time.The outlet valve 15 is then closed, fluid is moved from the servoreservoir 90 to the hydraulic fluid reservoir 52, and the process isrepeated over again. The outlet valve may also be adapted to functioningpassively and to open related to a volume decrease in the foodreservoir.

The above mentioned moving of fluid from the servo reservoir 90 to thehydraulic fluid reservoir 52 is preferably done in one of two ways:either the food entering the Food reservoir 12 from the inlet 11 presseson the flexible wall 552 of the servo reservoir 90 thus emptying fluidtherefrom to the hydraulic fluid reservoir 52 via the return conduit118; or the food sensor 117 sends signals to the pump 44 when food is toenter the food reservoir 12 the pump 44 thus pumping out to said foodcorresponding amount of fluid from the servo reservoir 90 to thehydraulic fluid reservoir 52 via conduits 44 a, 44 b. If the emptying ofthe servo reservoir 90 is done in one of the above ways, entry ofalready treated food from the intestine 210 into the food reservoir 12is avoided.

When the food contained in the food reservoir has been sufficientlytreated, and if no optional outlet valve 15 is present, the servoreservoir 90 is filled with fluid stepwise, i.e. step by step in smallsteps so that the food reservoir 12 is emptied or at least essentiallyemptied in small steps which results in that the sufficiently treatedfood is received by the intestine in small subsequent steps therebymaking it possible for the intestine to treat it without difficulty,i.e. the food reservoir is adapted to empty step by step, small portionsat a time. Thereafter, fluid is moved from the servo reservoir 90 to thehydraulic fluid reservoir 52, and the process is repeated over again.

The above mentioned moving of fluid from the servo reservoir 90 to thehydraulic fluid reservoir 52 is preferably done in one of two ways:either the food entering the food reservoir 12 from the inlet 11 presseson the flexible wall 552 of the servo reservoir 90 thus emptying fluidtherefrom to the hydraulic fluid reservoir 52 via the return conduit118; or the food sensor 117 sends signals to the pump 44 when food is toenter the food reservoir 12 the pump 44 thus pumping out to said foodcorresponding amount of fluid from the servo reservoir 90 to thehydraulic fluid reservoir 52 via conduits 44 a, 44 b. If the emptying ofthe servo reservoir 90 is done in one of the above ways, entry ofalready treated food from the intestine 210 into the food reservoir 12is avoided.

As mentioned above, a return conduit 118 may be arranged between thefluid reservoir 52 and the servo reservoir 90 if the food reservoir ofthe artificial stomach is adapted to increase in volume when filled withfood when the patient is eating, thereby causing a change in the volumeof the servo reservoir, in turn moving fluid between said servoreservoir and said hydraulic fluid reservoir via said return conduit118. Said return conduit 118 is preferably of smaller diameter than theconduits 44 a, 44 b.

Corresponding processed can be applied to the embodiments describedabove with reference to FIGS. 5 and 6.

Optionally, the pump 44 may be comprised in an operating unit (notshown), implanted subcutaneously under the patient's skin. The operatingunit may also comprise various additional components as e.g. injectionport, a special container, as described above, and/or a switch forcontrolling the artificial stomach 10 (not shown).

Optionally, a pumping reservoir may be provided, preferablysubcutaneously, like in the embodiment described above with reference toFIGS. 30a -c.

Optionally, the inlet 11 and the outlet 13 of the food reservoir 12 maybe provided with non return valves 14 and 15, respectively. Furthermore,in addition the food reservoir 12 may also be provided with a burpoutput 566, which may comprise a burp valve 568, which bypasses theinlet valve 14 to allow gases from the food reservoir 12 to leavethrough the oesophagus 202.

In FIG. 34 a flow chart illustrating steps performed when implanting anartificial stomach in accordance with the present invention. First in astep 102, an opening is cut in the abdominal wall. Next, in a step 104an area around the stomach is dissected. Thereupon, in a step 106 atleast one artificial stomach in accordance with the invention is placedin contact with the stomach wall, in particular the fundus wall. Thestomach wall is then sutured in a step 108. As can be seen from FIGS. 5,6 and 33, in some embodiments of the invention an outer wall enclosesboth the food reservoir and a servo reservoir, the servo reservoirregulating the size of the food reservoir, the food reservoir and theservo reservoir being separated by a flexible inner wall, where furtherboth the food reservoir wall and the servo reservoir wall comprise partsof the outer wall and the flexible inner wall. As can be seen from saidFIGS. 5, 6 and 33, the servo reservoir may be a bellow, and theregulating means may be a gear or a fluid. The servo reservoir isadapted to have a variable size and to be filled with different amountsof fluid. The servo reservoir is adapted to have a shape allowingvariation in size without limitation from surrounding fibrosis, coveringthe implant when implanted. The artificial stomach further comprises ahydraulic fluid reservoir, hydraulically connected to said servoreservoir and a pump for fluid connecting the fluid supply reservoir tothe servo reservoir, wherein said pump for fluid connecting thehydraulic fluid reservoir to the servo reservoir is adapted toreversible move fluid between the servo reservoir and the hydraulicfluid reservoir.

In some embodiments, an outer wall encloses both the food reservoir anda servo reservoir for regulating the size of the food reservoir, thefood reservoir and the servo reservoir being separated by a flexibleinner wall, where further both the food reservoir wall and the wall ofthe servo reservoir comprise parts of the outer wall and the flexibleinner wall, wherein said servo reservoir is adapted to be filled withfluid in small steps, wherein the food reservoir is adapted to beemptied by the servo reservoir in small steps, when said servo reservoiris filled with said fluid in small steps, thereby emptying food in smallsteps into the intestine, when said artificial stomach is implanted.

According to one embodiment, a method of using the artificial stomach byregulating the artificial stomach postoperatively to slowly empty foodin the artificial stomach into the intestine or adapting the stomach toreceive food by filling the servo reservoir with fluid step by step insmall steps so that the food reservoir is emptied or at leastessentially emptied in small steps which results in food is received bythe intestine in small subsequent portions.

FIG. 35 is a side view of an embodiment of a fastening device for anartificial stomach according to the invention mounted to a body tissue.

A fastening device for the artificial stomach may comprise a first unitadapted to be implanted at a first side of the abdominal wall in thepatient, and where a second unit is adapted to be implanted in theabdominal cavity of the patient at a second side of the abdominal wall,and where the artificial stomach is fastened to the fastening device.

A fastening device 120 for the artificial stomach may be placed in theabdomen, thorax, muscle fascia (e.g. in the abdominal wall), preferablysubcutaneously, or at any other suitable location.

The fastening device 120 comprises a first unit 122 preferablysubcutaneously implanted at a first side of a body tissue 124 in thepatient, such as the rectus abdominis muscle running vertically on eachside of the anterior wall of the human abdomen. In other words, thefirst unit is positioned between the skin 126 of the patient and thebody tissue 124.

A second unit 128 is implanted in a body cavity 130 of the patient at asecond side of the body tissue 124, i.e., that the side opposite of theside at which the first unit 122 is provided.

The first and/or second units 122, 128 preferably have circular orelliptical cross-sectional shape when viewed from outside the patient'sbody. Combined with a smoothly curved sectional shape, this avoids anysharp corners on the units 122, 128, which could cause injuries to thepatient in which the fastening device 120 is implanted.

The first and second units 122, 128 may be covered by a cover 132 madeof for example silicone or another material providing protection. Thecover 132, which preferably is resilient so as to follow the contours ofthe first and second units, also seals the fastening device 120 whichalso may be a control assembly, thereby protecting possible electronicsand other sensitive components of the possible control assembly.

If a cover encloses the first and second units 122, 128, these will bekept together mechanically, thereby assisting an interconnecting device134 in its interconnecting function.

The interconnecting device 134 constitutes a mechanical interconnectionbetween the first and second units 122, 128 so that the fastening device120 is kept in place by the body tissue 124. The interconnecting devicehas a cross-sectional area which is smaller than the cross-sectionalarea of the first unit and the second unit in a plane parallel to theextension of the body tissue. In this way, a hole 136 in the body tissue124 through Which the interconnecting device 134 extends can besufficiently small so that it is avoided that one or the other of theunits 122, 128 “slips through” the body tissue 124. Also, thecross-sectional shape of the interconnecting device 134 is preferablycircular so as to avoid damage to the body tissue 124.

The interconnecting device 134 can be integral with one of the first andsecond units 122, 128. Alternatively, the interconnecting device 134 isa separate part, which is connected to the first and second units 122,128 during implantation of the fastening device 120.

In a preferred embodiment, the interconnecting device 134 is hollow soas to house various wires, hoses etc. electrically or hydraulicallyinterconnecting the first and second units 122, 128 case the fasteningdevice 120 also is a control assembly.

Alternatively or additionally, the interconnecting device 134 is made ofan elastic material, such as rubber, so that the fastening device 120can adapt to the movements of the patient in which it is implanted.

The artificial stomach 10 is fastened to the fastening device 120 e.g.by using screws 138, rivets or the like. The artificial stomach maycomprise different material in layers, wherein at least one of said foodreservoir, a servo reservoir for controlling the food reservoir and ahydraulic fluid reservoir for controlling the servo reservoir, of saidartificial stomach may be provided with at least one layer. The at leastone layer may comprise a Parylene layer, or a polytetrafluoroethylenelayer, or a polyurethane layer, or a silicon layer, or a metal layer, ora Teflon® layer.

The metal layer may comprise any of gold, silver, and titanium, or acombination thereof.

The artificial stomach may be provided with a plurality of layers. Theartificial stomach may comprise an outer surface layer of polyurethane,Teflon®, or polytetrafluoroethylene, Parylene, silicone, metal, or acombination thereof.

The artificial stomach may comprise an inner surface layer ofpolyurethane, Teflon®, or polytetrafluoroethylene, Parylene, silicone,metal, or a combination thereof.

The artificial stomach may comprise an inner surface layer ofpolytetrafluoroethylene and an outer layer of silicone.

The artificial stomach may comprise an inner surface layer ofpolytetrafluoroethylene, an intermediate layer of silicone, and an outerlayer of Parylene.

The artificial stomach may comprise an inner surface layer ofpolyurethane and an outer layer of silicone.

The artificial stomach may comprise an inner surface layer ofpolyurethane, an intermediate layer of silicone, and an outer layer ofParylene.

The artificial stomach may comprise, an outer layer that includes abiocompatible material.

Please note that all the embodiments or features of an embodiment aswell as any method or step of a method could be combined in any way ifsuch combination is not clearly contradictory. Please also note that thedescription in general should be seen as describing both an apparatus ordevice adapted to perform a method as well as this method in itself.

While specific embodiments of the invention have been illustrated anddescribed herein, it is realized that numerous other embodiments may beenvisaged and that numerous additional advantages, modifications andchanges will readily occur to those skilled in the art without departingfrom the spirit and scope of the invention. Therefore, the invention inits broader aspects is not limited to the specific representativedevices and illustrated examples shown and described herein.Accordingly, various modifications may be made without departing fromthe spirit or scope of the general inventive concept as defined by theappended claims and their equivalents. It is therefore to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within a true spirit and scope of the invention.Numerous other embodiments may be envisaged without departing from thespirit and scope of the invention.

The invention claimed is:
 1. An artificial stomach for replacing thenormal stomach of a patient, comprising: a food reservoir adapted tocollect food, an inlet connected to a first opening of the foodreservoir and further being adapted to upstream connect to the patient'sgastrointestinal tract, and an outlet connected to a second opening ofthe food reservoir and further being adapted to downstream connect tothe patient's gastrointestinal tract, wherein an outer wall enclosesboth the food reservoir and a servo reservoir for regulating the size ofthe food reservoir, the food reservoir and the servo reservoir beingseparated by a flexible inner wall, where further both the foodreservoir wall and the wall of the servo reservoir comprise parts of theouter wall and the flexible inner wall.
 2. The artificial stomachaccording to claim 1, wherein the servo reservoir is a bellow.
 3. Theartificial stomach according to claim 1, wherein the emptying of thefood reservoir is direct or indirect regulated by a gear construction.4. The artificial stomach according to claim 3, wherein the gearconstruction is driven by a motor.
 5. The artificial stomach accordingto claim 4, comprising a servo system connected to said motor, to saveforce against longer stroke.
 6. The artificial stomach according toclaim 4, comprising a servo system connected to said motor and a driveshaft connected to said servo system.
 7. The artificial stomachaccording to claim 4, wherein the drive shaft direct or indirect affectsthe emptying of said food reservoir.
 8. The artificial stomach accordingto claim 7, wherein the drive shaft comprises two ends comprising athread, spiral ridges turning in different directions at the two ends,further comprising a nut placed on the shaft at each end of the driveshaft, the food reservoir comprising two movable walls of saidreservoir, wherein said nuts is adapted to be placed onto said movingwalls, the motor adapted to change the volume of said food reservoir,when turning said drive shaft placed into said nuts, by moving saidmovable walls.
 9. The artificial stomach according to claim 1, whereinthe servo reservoir is adapted to have a variable size and to be filledwith different amounts of fluid.
 10. The artificial stomach according toclaim 9, wherein the servo reservoir is adapted to have a shape allowingvariation in size without limitation from surrounded fibrosis, coveringthe implant when implanted.
 11. The artificial stomach according toclaim 9, the artificial stomach further comprising a hydraulic fluidreservoir, hydraulically connected to said servo reservoir and a pumpfor fluid connecting the fluid supply reservoir to the servo reservoir.12. The artificial stomach according to claim 11, wherein said pump forfluid connecting the hydraulic fluid reservoir to the servo reservoir isadapted to reversible move fluid between the servo reservoir and thehydraulic fluid reservoir.
 13. The artificial stomach according to claim9, wherein said servo reservoir is adapted to be regulated by manuallypressing a pumping reservoir in fluid connection with the servoreservoir.
 14. The artificial stomach according to claim 13, furthercomprising a reversed servo, wherein a small volume in the pumpingreservoir is adapted to be moved manually to the servo reservoir in aclosed system, compressed with a higher force per area unit and whereinsaid servo reservoir is adapted to create a larger volume change in asecond closed system, having less force per area unit.
 15. Theartificial stomach according to claim 12, wherein the outer wall isrigid.
 16. The artificial stomach according to claim 15, wherein thestomach food part comprises the food reservoir and the servo reservoir,and where the hydraulic fluid reservoir is separated from the stomachfood part by the rigid outer wall and is further enclosed by a fluidreservoir wall.
 17. The artificial stomach according to claim 16,wherein said food reservoir is adapted to increase in volume when filledwith food when the patient is eating, thereby causing a reduction in thevolume of the servo reservoir, in turn moving fluid from said servoreservoir to said hydraulic fluid reservoir.
 18. The artificial stomachaccording to claim 1, being implantable in the patient's abdomen. 19.The artificial stomach according to claim 1, wherein the inlet isfurther adapted to upstream connect to the oesophagus.
 20. Theartificial stomach according to claim 1, wherein the inlet is furtheradapted to upstream connect to the intestine.